Comments

There is a species described by Zeller from Oregon and known only from the type collection: Agaricus cervinifolius. When I studied the type specimen, it seemed related to A. californicus, but somewhat different — it had some scales. Yours reminds me more of A. cervinifolius than A. californicus, but we don’t know yet exactly how to recoginze A. cervinifolius (if it is different — and yours does seem different from A. californicus).

There is one other possibility, an undescribed species I’ll call “D” for now. Spore size data can separate the two.